I'm condemned to being a grumpy old man. It's my step-granddaughter's fault. She's nine, already has a Granddad and a Pop - so she decided on "Grumpy" for me and it looks like it will stick, my year-old grandson is already attempting "umpy".
It's bound to, but don't be a curmudgeon. I think that makes people even less happy. Why not enjoy the time between now and what comes next. Focus on what you have; I know you have a sharp mind and that outweighs most other losses of age put together. Positive attitude, my dear, cannot be overstated.
Getting older in my opinion does not suck. it gives you freedom that you have never had before. be it as a curmudgeon or otherwise, it is entirely your choice.
I hate to tell you this but being a curmudgeon doesn't pay well.. in fact it's a voluntary position rather than a career :P Your wife sounds like an angel - you know you are lucky to have her..